| Year | Value | | 2022 | 6,846 | | 2021 | 6,601 | | 2020 | 6,326 | | 2019 | 6,052 | | 2018 | 5,821 | | 2017 | 5,572 | | 2016 | 5,317 | | 2015 | 5,122 | | 2014 | 4,909 | | 2013 | 4,681 | | 2012 | 4,597 | | 2011 | 4,635 | | 2010 | 4,680 | | 2009 | 4,700 | | 2008 | 4,697 | | 2007 | 4,673 | | 2006 | 4,604 | | 2005 | 4,552 | | 2004 | 4,588 | | 2003 | 4,644 | | 2002 | 4,650 | | 2001 | 4,661 | | 2000 | 4,636 | | 1999 | 4,508 | | 1998 | 4,383 | | 1997 | 4,315 | | 1996 | 4,277 | | 1995 | 4,285 | | 1994 | 4,336 | | 1993 | 4,406 | | 1992 | 4,479 | | 1991 | 4,534 | | 1990 | 4,586 | | 1989 | 4,615 | | 1988 | 4,605 | | 1987 | 4,587 | | 1986 | 4,563 | | 1985 | 4,529 | | 1984 | 4,469 | | 1983 | 4,358 | | 1982 | 4,203 | | 1981 | 4,053 | | 1980 | 3,955 | | 1979 | 3,945 | | 1978 | 4,034 | | 1977 | 4,166 | | 1976 | 4,256 | | 1975 | 4,242 | | 1974 | 4,133 | | 1973 | 3,934 | | 1972 | 3,663 | | 1971 | 3,390 | | 1970 | 3,173 | | 1969 | 3,008 | | 1968 | 2,871 | | 1967 | 2,769 | | 1966 | 2,702 | | 1965 | 2,666 | | 1964 | 2,672 | | 1963 | 2,733 | | 1962 | 2,830 | | 1961 | 2,910 | | 1960 | 2,921 |
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